The goal of this project is the synthesis, isolation, purification, and characterization of a number of different research compounds of interest to the carcinogenesis research community. Some of these chemical standards will be new to the program and others will be synthesized to replace depleted chemical stocks. The contractors selected from this recompetition will have two major responsibilities. First, they will be responsible for the resynthesis of polycyclic aromatic hydrocarbons (PAH)-derivatives (primarily by established procedures) for the restocking of the NCI's Chemical Carcinogen Reference Standards Repository as necessary, and they will develop synthesis or purification procedures for the preparation of a wide spectrum of other selected chemical carcinogens, chemopreventive agents and certain of their metabolites or derivatives. The types of compounds, referred to as PAH metabolites, include dihydrodiols, phenols, quinones, enantiomeric diolepoxides, epoxides, dialdehydes resulting from the cleavage of vicinally-disubstituted oxygenated derivatives, alkyl- and hydroxyalkyl-substituted parent hydrocarbons, conjugated derivatives (chemical or biosynthetic such as glutathiones, glucuronides, and sulfates), and labeled (3H, 13C, 4C) analogs. The other focus of the workscope will include the synthesis of chemicals from selected carcinogen and chemopreventive classes.